Everyone knows what to do if one morning the sky would be absolutely full of UFOs: run as fast as you can. However, what would happen if the invasion started while you are in the flat of the girl of your dreams, the one you have just met?

Julio (Julian Villagran) — handsome, fit, and aging — wakes up to a strange crack of light inching across an unfamiliar ceiling like a shadow in a Murnau film. The bedroom door is creaking open, but, to Julio’s palpable dismay, this isn’t his door, and it isn’t his bedroom. The comedy begins immediately, Julio’s brain clearly trying to recall the name of whoever is making those rattling sounds just outside in the kitchen. This turns out to be Julia (Michelle Jenner); Julio can’t remember her name, but she’s so stunning in her nightshirt and panties that he’s more than willing to pretend he can. He shares with her an awkward coffee but fails to get her interested in maybe doing this again. Then he tries to use her computer to get out of there, but finds that the internet is down. So is the TV signal. So are the phones. Julio and Julia run through all of their usual tech crutches but nothing seems to be working. Then, out the window, there’s an answer: the flying saucer hovering above the city center is likely jamming all the waves.

Neither the saucer nor the town center will ever be reached by the foggy-brained lovers. It would likely be the only sane reaction of any adult human, no matter how hungover, to hunker down and fortify in the event of an unexplainable disaster. Julia and Julio do just that, but that shouldn’t indicate that Vigalondo considers either of them particularly sane. The sly point of having the aliens around seems to be that no matter what new adversities we normal humans have to face, we’re bound to turn them into comedies of errors. Maybe, Vigalondo likes to suggest, the aliens above the city are smart enough to realize this: with a minimum of effort, they can neutralize us by playing on our fears. They just hover there ominously and wait for the humans to stew amongst themselves so long that they can’t resist bringing out their guns and their bombs.

The bombs in Extraterrestrial are all homemade, supplied by Julia’s boyfriend, Angel (Carlos Areces), a shifty conspiracy theorist who shows up unexpectedly and closely resembles the kind of guy who gets off on apocalyptic horror movies: he invites the invasion because it will give him a chance to prove his manhood. Needless to say, Julia is very careful to keep from him the fact that, the previous night with Julio, she robbed him of it a few times over. Angel obliviously invites Julio to stay with him and Julia to wait out the potential alien attack. For one thing, no compassionate person would let another travel across town with an invasion going on. For another, it’s always beneficial to have another person around for defensive purposes. But it’s the downside of having two men in a house with only one woman that interests Vigalondo. At its core, the movie functions on jokes like this: if everyone weren’t deceiving each other, the spacecraft above the city might be any other giant chunk of metal in the distance, as innocuous as a skyscraper or a sports stadium.

Extraterrestrial is a well-built series of precise machinations, a clever bunch of setups that lands innumerable complex and difficult jokes (how do you trick a man into blowing up your own apartment by making him think you don’t want it done?), but makes the easy point that humanity’s worst enemy will always be himself. Vigalondo isn’t reaching for any more than this; he’s far too fascinated with the small world he’s created under the specter of something giant. In multiple ways, he’s made the most modest War of the Worlds film imaginable.